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Abstract:

Golf balls include: (a) a golf ball having a first set of construction
specifications; (b) a coating of the golf ball having an exterior surface
and (c) the exterior surface having an enhanced micro surface roughness.
The enhanced micro surface roughening affects the aerodynamic properties
of the ball as compared to golf balls having the same set of construction
specifications but without enhanced micro surface roughness.

Claims:

1. A golf ball, comprising: a core; a cover encasing the core; and a
coating encasing the cover, wherein the coating includes a resin and a
plurality of surface roughening particles; wherein the golf ball has a
first set of construction specifications; wherein the plurality of
surface roughening particles are present in the coating in a sufficient
amount so that an exterior surface of the golf ball has a first micro
surface roughness at least 1.2 times larger than a micro surface
roughness of an exterior surface of a first comparative ball having the
first set of construction specifications but not including the surface
roughening particles; wherein the plurality of surface roughening
particles are present in a sufficient amount in the coating such that the
golf ball exhibits an overall average coefficient of lift to coefficient
of drag that is at least 99.3% of the largest overall average coefficient
of lift to coefficient of drag exhibited by: (a) the first comparative
ball; (b) a second comparative ball having the first set of construction
specifications and a micro surface roughness of about 2.0 times larger
than the micro surface roughness of the first comparative ball; (c) a
third comparative ball having the first set of construction
specifications and a micro surface roughness of about 3.0 times larger
than the micro surface roughness of the first comparative ball; and (d) a
fourth comparative ball having the first set of construction
specifications and a micro surface roughness of about 4.0 times larger
than the micro surface roughness of the first comparative ball; wherein
micro surface roughness include deviations from an ideal surface of 0.25
mm or less and wherein coefficient of lift and coefficient of drag
measurements are measured using standard USGA indoor test range testing
protocols with balls launched in a pole orientation at an initial launch
velocity of 258 ft/s, an initial launch angle of 9.7.degree., and an
initial launch spin of 46 revolutions/s.

2. The golf ball of claim 1, wherein the surface roughening particles
have an average particle size of 400 nm to 160 microns.

3. The golf ball of claim 1, wherein the surface roughening particles
comprise 1 to 30 wt % of a total weight of the coating.

5. The golf ball of claim 1, wherein the coating has an average thickness
of 8 to 50 microns.

6. The golf ball of claim 1, wherein the coating includes the surface
roughening particles contained within the resin.

7. The golf ball of claim 1, wherein the coating comprises a layer of the
resin applied to an outer surface of a golf ball body of the golf ball
and the plurality of surface roughening particles embedded in an outer
surface of the layer of the resin.

8. The golf ball of claim 1, wherein a predetermined area of the exterior
surface of the golf ball has the first micro surface roughness, and
wherein the predetermined area of the exterior surface is smaller than a
surface area of the entire exterior surface.

9. The golf ball of claim 8, wherein the predetermined area comprises an
area covering at least 7.5% of the exterior surface.

10. The golf ball of claim 1, wherein the first micro surface roughness
constitutes an average micro surface roughness of an area covering at
least 7.5% of an entire surface area of the ball, wherein the area
covering at least 7.5% of the entire surface areas is dispersed over at
least 36 discrete locations on the surface of the ball.

11. The golf ball of claim 1, wherein the first micro surface roughness
constitutes an average micro surface roughness of an area covering at
least 7.5% of an entire surface area of the ball, wherein the area
covering at least 7.5% of the entire surface area includes surface area
surrounding at least 36 different dimples dispersed around the surface of
the ball.

12. A golf ball, comprising: a core; a cover encasing the core; and a
coating encasing the cover, wherein the coating includes a resin and a
plurality of surface roughening particles; wherein the golf ball has a
first set of construction specifications; wherein the plurality of
surface roughening particles are present in the coating in a sufficient
amount so that an exterior surface of the golf ball has a first micro
surface roughness at least 1.2 times larger than a micro surface
roughness of an exterior surface of a first comparative ball having the
first set of construction specifications but not including the surface
roughening particles; wherein the plurality of surface roughening
particles are present in a sufficient amount in the coating such that the
golf ball exhibits a coefficient of lift at a location from an initial
launch point that is at least 95% of the largest coefficient of lift at
the location from an initial launch point exhibited by: (a) the first
comparative ball; (b) a second comparative ball having the first set of
construction specifications and a micro surface roughness of about 2.0
times larger than the micro surface roughness of the first comparative
ball; (c) a third comparative ball having the first set of construction
specifications and a micro surface roughness of about 3.0 times larger
than the micro surface roughness of the first comparative ball; and (d) a
fourth comparative ball having the first set of construction
specifications and a micro surface roughness of about 4.0 times larger
than the micro surface roughness of the first comparative ball; wherein
micro surface roughness include deviations from an ideal surface of 0.25
mm or less and wherein coefficient of lift measurements are measured at
the location from an initial launch point using standard USGA indoor test
range testing protocols with balls launched in a pole orientation at an
initial launch velocity of 242 ft/s, an initial launch angle of
11.3.degree., and an initial launch spin of 44.7 revolutions/s.

13. The golf ball of claim 12, wherein the surface roughening particles
have an average particle size of 400 nm to 160 microns.

14. The golf ball of claim 12, wherein the surface roughening particles
comprise 1 to 30 wt % of a total weight of the coating.

15. The golf ball of claim 12, wherein the coating includes the surface
roughening particles contained within the resin.

16. The golf ball of claim 12, wherein the first micro surface roughness
constitutes an average micro surface roughness of an area covering at
least 7.5% of an entire surface area of the ball, wherein the area
covering at least 7.5% of the entire surface areas is dispersed over at
least 36 discrete locations on the surface of the ball.

17. A golf ball, comprising: a core; a cover encasing the core; and a
coating encasing the cover, wherein the coating includes a resin and a
plurality of surface roughening particles; wherein the golf ball has a
first set of construction specifications; wherein the plurality of
surface roughening particles are present in the coating in a sufficient
amount so that an exterior surface of the golf ball has a first micro
surface roughness at least 1.2 times larger than a micro surface
roughness of an exterior surface of a first comparative ball having the
first set of construction specifications but not including the surface
roughening particles; wherein the plurality of surface roughening
particles are present in a sufficient amount in the coating such that the
golf ball exhibits a post-apex average coefficient of drag that is at
least 95% of the largest post-apex average coefficient of drag exhibited
by: (a) the first comparative ball; (b) a second comparative ball having
the first set of construction specifications and a micro surface
roughness of about 2.0 times larger than the micro surface roughness of
the first comparative ball; (c) a third comparative ball having the first
set of construction specifications and a micro surface roughness of about
3.0 times larger than the micro surface roughness of the first
comparative ball; and (d) a fourth comparative ball having the first set
of construction specifications and a micro surface roughness of about 4.0
times larger than the micro surface roughness of the first comparative
ball; wherein micro surface roughness include deviations from an ideal
surface of 0.25 mm or less and wherein coefficient of drag measurements
are measured using standard USGA indoor test range testing protocols with
balls launched in a pole orientation at an initial launch velocity of 258
ft/s, an initial launch angle of 9.7.degree., and an initial launch spin
of 46 revolutions/s.

18. The golf ball of claim 17, wherein the surface roughening particles
have an average particle size of 400 nm to 160 microns.

19. The golf ball of claim 17, wherein the surface roughening particles
comprise 1 to 30 wt % of a total weight of the coating.

20. The golf ball of claim 17, wherein the first micro surface roughness
constitutes an average micro surface roughness of an area covering at
least 7.5% of an entire surface area of the ball, wherein the area
covering at least 7.5% of the entire surface areas is dispersed over at
least 36 discrete locations on the surface of the ball.

Description:

RELATED APPLICATION DATA

[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/184,254 filed Jul. 15, 2011 in the name of Derek
Fitchett and Johannes Anderl, which is a continuation-in-part of U.S.
patent application Ser. No. 12/569,955 filed Sep. 30, 2009 in the name of
Derek Fitchett. These parent applications are entirely incorporated
herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates generally to golf balls. Particular
example aspects of this invention relate to golf balls having a coating
with micro surface roughness that improves the aerodynamic performance of
the ball.

BACKGROUND

[0003] Golf is enjoyed by a wide variety of players--players of different
genders and dramatically different ages and/or skill levels. Golf is
somewhat unique in the sporting world in that such diverse collections of
players can play together in golf events, even in direct competition with
one another (e.g., using handicapped scoring, different tee boxes, in
team formats, etc.), and still enjoy the golf outing or competition.
These factors, together with the increased availability of golf
programming on television (e.g., golf tournaments, golf news, golf
history, and/or other golf programming) and the rise of well-known golf
superstars, at least in part, have increased golf's popularity in recent
years.

[0004] Golfers at all skill levels seek to improve their performance,
lower their golf scores, and reach that next performance "level."
Manufacturers of all types of golf equipment have responded to these
demands, and in recent years, the industry has witnessed dramatic changes
and improvements in golf equipment. For example, a wide range of
different golf ball models now are available, with balls designed to
complement specific swing speeds and/or other player characteristics or
preferences, e.g., with some balls designed to fly farther and/or
straighter; some designed to provide higher or flatter trajectories; some
designed to provide more spin, control, and/or feel (particularly around
the greens); some designed for faster or slower swing speeds; etc. A host
of swing and/or teaching aids also are available on the market that
promise to help lower one's golf scores.

[0005] Being the sole instrument that sets a golf ball in motion during
play, golf clubs also have been the subject of much technological
research and advancement in recent years. For example, the market has
seen dramatic changes and improvements in putter designs, golf club head
designs, shafts, and grips in recent years. Additionally, other
technological advancements have been made in an effort to better match
the various elements and/or characteristics of the golf club and
characteristics of a golf ball to a particular user's swing features or
characteristics (e.g., club fitting technology, ball launch angle
measurement technology, ball spin rate measurement technology, ball
fitting technology, etc.).

[0006] Modern golf balls generally comprise either a one-piece
construction or multiple layers including an outer cover surrounding a
core. Typically, one or more layers of paint and/or other coatings are
applied to the outer surface of the golf ball. For example, in one
typical design, the outer surface of the golf ball is first painted with
at least one clear or pigmented basecoat primer followed by at least one
application of a clear coating or topcoat. The clear coating may serve a
variety of functions, such as protecting the cover material (e.g.,
improving abrasion resistance or durability), improving aerodynamics of
ball flight, preventing yellowing, and/or improving aesthetics of the
ball.

[0007] One common coating utilizes a solvent borne two-component
polyurethane, which is applied to the exterior of a golf ball. The
coating may be applied, for example, by using compressed air or other gas
to deliver and spray the coating materials. The balls and spray nozzles
may be rotated or otherwise articulated with respect to one another to
provide an even coating layer over the entire ball surface.

[0008] Dimples were added to golf balls to improve the aerodynamics as
compared with smooth balls. Variations of the dimples have been
introduced over the years relating to their size, shape, depth, and
pattern. Other concepts have included the inclusion of small dimples or
other structures within dimples to provide different aerodynamic
performance. Such small dimples or other structures, however, often fill
up during application of a paint or top coat to the outer surface of the
ball, thus destroying or substantially reducing the intended
dimple-in-dimple aerodynamic effect of the balls.

[0009] While the industry has witnessed dramatic changes and improvements
to golf equipment in recent years, some players continue to look for
increased distance on their golf shots, particularly on their drives or
long iron shots, and/or improved spin or control of their shots,
particularly around the greens and/or at initial launch. Accordingly,
there is room in the art for further advances in golf technology.

SUMMARY

[0010] The following presents a general summary of aspects of the
disclosure in order to provide a basic understanding of the disclosure
and various aspects of this invention. This summary is not intended to
limit the scope of the invention in any way, but it simply provides a
general overview and context for the more detailed description that
follows.

[0011] Aspects of this disclosure are directed to imparting enhanced micro
surface roughness on a golf ball by roughening the exterior surface of
the ball through abrasion to include deviations in the exterior surface
of the ball in a sufficient amount such that the micro surface roughness
of the ball is increased. Methods of abrading include rubbing the ball
against an abrasive material, rolling or tumbling the ball against an
abrasive material, and/or blasting the ball with abrasive material.
Abrasive material can include, for example, a loose aggregate of abrasive
particulate (e.g. sand, crushed minerals, etc.), a bonded abrasive, a
coated abrasive (e.g. sand paper), a pumice, a sharp surface, and/or a
scored surface.

[0012] Aspects of this disclosure are directed to selectively increasing
micro surface roughness of predetermined areas of the ball. The
predetermined area can be less than a surface area of the entire exterior
surface area of the ball. Example predetermined areas can include an area
covering at least one of two opposite poles of the golf ball, an area
covering at least a portion of a seam of the golf ball, an area covering
at least a portion of the lands between dimples of the golf ball, and an
area covering at least a portion of one or more of the dimples. The
predetermined area can be in the form of a symmetrical or asymmetrical
pattern on the exterior surface of the golf ball.

[0013] Aspects of this disclosure are directed to a stencil used to cover
the exterior surface of the golf ball during selective micro surface
roughening. The stencil can leave exposed the predetermined area for
selective roughening and cover the remaining area to protect the
remaining area from being roughened or being subject to further
roughening.

[0014] Aspects of this disclosure are directed to optimizing micro surface
roughness so that a ball exhibits a particular enhanced aerodynamic
property in accordance with a peak condition for such property as
compared to comparative balls having different aspects of micro surface
roughness. Aspects of micro surface roughness can be varied in order to
determine an optimized micro surface roughness so that the ball exhibits
the enhanced aerodynamic property or enhanced aerodynamic property in
accordance with a peak condition for such property as compared to
comparative balls having different aspects of micro surface roughness.

[0015] As used herein, balls will be considered to have the "same ball
construction" if they are made to the same construction specifications
with the exception of the roughening material incorporated into the
structure (e.g., same core size and materials, same intermediate layer(s)
size(s) and material(s), same cover size and material, same dimple
patters, etc.) or use of a processes that impart increased micro surface
roughness to the exterior surface of a ball. Also, as used herein, two
dimples will be considered to be of different dimple "types" if they
differ from one another in at least one of dimple perimeter shape or
dimple profile (cross sectional) shape, including but not limited to
different dimple depths, different dimple diameters, or different dimple
radii. Two dimples will be considered to be of the "same type" if the CAD
or other "blueprint" data or specifications for making the mold cavity
for forming the dimples indicates that the dimples are intended to have
the same size and shape (post mold treatments, such as coating or
painting, may slightly alter the dimensions from dimple to dimple within
a given dimple type, and these post-molding changes do not convert
dimples of the same "type" to dimples of different "types").

[0016] Other aspects of this invention are directed to methods for making
golf balls including particles to increase micro surface roughness of the
ball, e.g., by applying a coating comprising a resin and particles to a
surface of a golf ball, by incorporating roughness increasing particles
into the cover member, by incorporating roughness into the exterior
surface of the ball by abrasion, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A more complete understanding of the present invention and certain
advantages thereof may be acquired by referring to the following detailed
description in consideration with the accompanying drawings, in which:

[0019] FIGS. 2 and 2A schematically illustrate a cross-sectional view of a
golf ball in accordance with FIG. 1 having a coating thereon.

[0020]FIG. 3 schematically illustrates a cross-sectional view of a
portion of a golf ball having a cover layer and coating in accordance
with FIG. 1 having particles contained within a resin.

[0021]FIG. 4 schematically illustrates a cross-sectional view of a
portion of a golf ball having a cover layer and coating in accordance
with FIG. 1 having particles applied onto the surface of a resin.

[0027]FIG. 10A is a diagram used in explaining measurement of surface
roughness and deviation of an actual surface from an "ideal" surface.

[0028]FIG. 10B is a diagram used in explaining various dimple parameters
of a golf ball in accordance with this invention.

[0029]FIG. 11A through 11D are charts illustrating macro surface
roughness and micro surface roughness features for various dimples of:
(a) roughened balls in accordance with examples of this invention and (b)
smooth control balls.

[0030]FIG. 12 is a graph illustrating the ratio of coefficient of lift
against coefficient of drag for roughened balls in accordance with
examples of this invention and smooth control balls at various Reynolds
number and/or other launch conditions.

[0031]FIG. 13 is a graph illustrating vertical trajectory for roughened
balls in accordance with examples of this invention and smooth control
balls as launched under conditions representative of those of an
"average" professional player.

[0032]FIG. 14 is a graph illustrating coefficient of lift v. carry
distance for roughened balls in accordance with examples of this
invention and smooth control balls as launched under conditions
representative of those of an "average" professional player.

[0033] FIG. 15 combines the data of FIGS. 13 and 14 on a single graph to
allow consideration of certain aspects and features of the measured data.

[0034]FIG. 16A through FIG. 16D depict example embodiments of golf ball
roughener systems in accordance with examples of this disclosure.

[0035] FIG. 17A through FIG. 17H depict embodiments of selective
application of micro surface roughness to predetermined areas of a golf
ball in accordance with examples of this disclosure.

[0036]FIG. 18A through FIG. 18G depict embodiments of stencils for
selective application of micro surface roughness to predetermined areas
of a golf ball in accordance with examples of this disclosure.

[0037]FIG. 19 is a graph illustrating levels of micro surface roughness
for a control ball and roughened balls in accordance with examples in
this disclosure.

[0038]FIG. 20A is a table including driver shot simulation data showing
differences in total carry and roll in yards in comparison to a control
ball for roughened balls in accordance with examples of this disclosure
in pole and seam position with different launch conditions.

[0039]FIG. 20B is a graph illustrating coefficient of lift to coefficient
of drag ratio for a roughened ball in accordance with examples of this
disclosure and a smooth control ball at various Reynolds number and/or
other launch conditions.

[0040]FIG. 20c is a graph illustrating coefficient of lift to coefficient
of drag ratio v. carry for a roughened ball in accordance with examples
of this disclosure and a smooth control ball.

[0041]FIG. 21A is table including driver shot simulation data for balls
in pole position with different launch conditions for a smooth control
ball and roughened balls in accordance with examples of this disclosure.

[0043]FIG. 21E and FIG. 21F are graphs illustrating coefficient of lift
to coefficient of drag ratio for a roughened ball in accordance with
examples of this disclosure and a smooth control ball at various Reynolds
number and/or other launch conditions.

[0044]FIG. 21G and FIG. 21H are tables including driver shot simulation
data for a smooth control ball and roughened with different launch
conditions in pole and seam position, respectively.

[0045] The reader is advised that the various parts shown in these
drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

[0046] In the following description of various example structures,
reference is made to the accompanying drawings, which form a part hereof,
and in which are shown by way of illustration various example golf ball
structures. It is to be understood that other specific arrangements of
parts and structures may be utilized and structural and functional
modifications may be made without departing from the scope of the present
invention. As some more specific examples, aspects of this invention may
be practiced on balls having any desired construction, any number of
pieces, any specific dimple design, and/or any desired dimple pattern.

General Description of Golf Balls and Manufacturing Systems and Methods

[0047] A variety of golf ball constructions have been designed to provide
particular playing characteristics. These characteristics generally
include control of the initial velocity and spin of the golf ball, which
can be optimized for various types of players. For instance, certain
players prefer or need a ball that has a high spin rate in order to
optimize launch angle and/or control and stop the golf ball around the
greens. Other players prefer or require a ball that has a low spin rate
and high resiliency to maximize distance and/or prevent excessive lift at
initial launch.

[0048] The carry distance and/or "feel" of some conventional two-piece
solid balls has been improved by altering the typical single layer core
and single cover layer construction to provide a multi-layer ball, e.g.,
a dual cover layer, a dual core layer, and/or a ball having one or more
intermediate mantle layers disposed between the cover and the core.
Three-piece and four-piece solid balls (and even five-piece balls) are
now commonly found and are commercially available. Aspects of this
disclosure may be applied to all types of ball constructions, including
wound, solid, and/or multi-layer ball constructions.

[0049]FIG. 1 shows an example of a golf ball 10 that includes a plurality
of dimples 18 formed on its outer surface. FIGS. 2 and 2A illustrate one
example golf ball 10 in accordance with this disclosure. As shown, this
example golf ball has a core 12, an intermediate layer 14, a cover 16
having a plurality of dimples 18 formed therein, and a topcoat 20 applied
over the exterior surface of the cover 16 of the ball 10. The golf ball
10 alternatively may be only one piece such that the core 12 represents
the entirety of the golf ball 10 structure (optionally with an overlying
coating layer 20), and the plurality of dimples 18 are formed on the core
12. The ball 10 also may have any other desired construction (e.g.,
two-piece solid construction, four-piece solid construction, a wound
construction, etc.). The thickness of the topcoat 20 typically is
significantly less than that of the cover 16 or the intermediate layer
14, and by way of example may range from about 5 to about 25 μm. The
topcoat 20 preferably will have a minimal effect on the depth and volume
of the dimples 18. Golf balls 10 according to this disclosure may include
one or more pieces for the core 12 (e.g., also called an "inner core," an
"outer core," etc.), one or more intermediate layers 14 (e.g., also
called "mantle layers" or "barrier layers," etc.), and one or more cover
layers 18 (e.g., also called an "inner cover," an "outer cover," etc.).

[0050] The golf ball 10 and the various components thereof may be made
from any desired materials without departing from this disclosure,
including, for example, materials that are conventionally known and used
in the golf ball art. As some more specific examples, the cover 16 of the
golf ball 10 may be made of any number of materials such as ionomeric,
thermoplastic, elastomeric, urethane, TPU, balata (natural or synthetic),
polybutadiene materials, or combinations thereof. Micro surface roughness
features as described in more detail below may be incorporated into the
cover layer 16, in accordance with at least some examples of this
disclosure. An optional primer or basecoat may be applied to the exterior
surface of the cover 16 of the golf ball 10 prior to application of the
coating layer 20. As some more specific examples, the cover layer 16 may
be formed of SURLYN® based ionomer resins, thermoplastic polyurethane
materials, and thermoset urethane materials, as are conventionally known
and used in the art.

[0051] A variety of coating materials may be used to form a coating 20
over the golf ball 10, non-limiting examples of which include
thermoplastics, thermoplastic elastomers (such as polyurethanes,
polyesters, acrylics, low acid thermoplastic ionomers, e.g., containing
up to about 15% acid, and UV curable systems), including coating layer
materials as are conventionally known or used in the art. The coating
layer 20 may constitute a paint layer, a clear coat layer, or other
desired material. The thickness of the coating layer 20 will typically
range from of about 5 to about 25 μm, and in some examples from about
10 to about 15 μm. The coating layer 20 may include additives, if
desired, such as flow additives, mar/slip additives, adhesion promoters,
thickeners, gloss reducers, flexibilizers, cross-linking additives,
isocyanates or other agents for toughening or creating scratch
resistance, optical brighteners, UV absorbers, and the like. The amount
of such additives usually ranges from 0 to about 5 wt %, often from 0 to
about 1.5 wt %. Also, micro surface roughness features as described in
more detail below may be incorporated into the coating layer 20, in
accordance with at least some examples of this disclosure.

Example Manufacturing Process

[0052] Golf balls in accordance with this disclosure may be produced in
any desired manner without departing from this disclosure, including in
generally conventional manners as are known and used in the art (with the
exception of the additional feature of incorporating micro surface
roughness into the ball construction, as will be explained in more detail
below). Some example methods are described in more detail below.

[0053] As an initial step in one example golf ball manufacturing process,
a golf ball central core is made, e.g., by a molding operation, such as
compression molding, hot press molding, injection molding, or other
procedures as are known and used in the art. Such cores may be made of
rubber materials, elastomeric resin materials (such as highly neutralized
acid polymer compositions including HPF resins (e.g., HPF1000, HPF2000,
HPF AD1027, HPF AD1035, HPF AD1040 and mixtures thereof, all produced by
E. I. DuPont de Nemours and Company), and the like. The cores may have
any desired physical properties (e.g., COR, density, sizes, diameters,
hardnesses, etc.) and/or additives, including properties and additives
that are conventionally known and used in the golf ball art.

[0054] If desired, one or more intermediate layers 14 may be formed over
the core 12 in golf ball constructions in accordance with at least some
examples of this disclosure. Such intermediate layers 14 may be formed by
molding or lamination procedures, such as injection molding. The
intermediate layers 14, when present, may be made from any desired
material including materials that are conventionally known and used in
the art, such as ionomer resins (e.g., SURLYN®'s, as described
above), polyurethanes, TPUs, rubbers, and the like. The intermediate
layers 14 may have any desired physical properties (e.g., COR, density,
thicknesses, hardnesses, etc.) and/or additives, including properties and
additives that are conventionally known and used in the art.

[0055] The next step in this example golf ball production process involves
forming a cover layer 16 around the golf ball interior (e.g., the core 12
and any present intermediate layers 14). The cover material 16 may be an
ionomeric resin (e.g., a SURLYN® material), a thermoplastic
polyurethane material, a thermosetting polyurethane material, a rubber
material, or the like. The core 12, including the center and any present
intermediate layers 14, may be supported within a pair of cover
mold-halves by a plurality of retractable pins. The retractable pins may
be actuated by conventional means known to those of ordinary skill in the
art. After the mold halves are closed together with the pins supporting
the ball interior, the cover material is injected into the mold in a
liquid or flowable state through a plurality of injection ports or gates,
such as edge gates or sub-gates. The mold halves will include structures
that result in formation of dimples 18 in the cover layer 16. In some
example structures in accordance with this disclosure, the cover material
may form a base material for carrying the micro surface roughness
increasing materials (e.g., the silica or other roughening particles).
The micro surface roughness increasing material may be included in all
areas of the cover material or in separated and discrete targeted areas
of the cover material, as will be described in more detail below.

[0056] The retractable pins may be retracted after a predetermined amount
of cover material has been injected into the mold halves to substantially
surround the ball interior. The flowable cover material is allowed to
flow and substantially fill the cavity between the ball interior and the
mold halves, while maintaining concentricity between the ball interior
and the mold halves. The cover material is then allowed to solidify
around the ball interior, and the golf balls are ejected from the mold
halves. As another option, the golf ball cover 16 may be formed by
casting procedures, e.g., as conventionally known and used in this art,
although the micro surface roughness increasing material may be
incorporated into the material used for the casting process, if desired.

[0057] As a next step, if desired, a finish material, such as paint and/or
one or more other coating layer(s) 20, may be applied to the golf ball
cover 16 surface. As another finishing step (which may take place before
or after one of the coating steps as described above), printing may be
applied to a golf ball. Any desired type of printing technique may be
used without departing from this disclosure, including printing
techniques such as pad printing and ink jet printing and/or other
printing techniques that are conventionally known and used in the art.
The finish materials (e.g., coating layer 20) may form a base material
for carrying the micro surface roughness increasing material, as will be
described in more detail below.

Detailed Description of Example Golf Balls and Methods According to
Aspects of the Invention

[0058] The term "golf ball body" as used herein means a golf ball before
applying the top coat (e.g., a ball structure including a core, one or
more intermediate layers, and a cover layer with dimples). In terms of
the discussion below, the term "coating" often will be used to identify
the top coat or last layer applied to the golf ball, but, as also
described below, if desired, another coating may be applied over the
roughened coating material or roughened cover layer, if desired, provided
that an overall micro surface roughened outer surface is still provided.
Often the terms "paint" or "painting" may be used synonymously with a
"coating" or "coating" process without departing from this invention.

[0059] The term "enhanced micro surface roughness" as used herein means
increased micro surface roughness created by the use of surface
roughening particles or processes that impart increased micro surface
roughness to the exterior surface of a ball.

[0060] As described above, the term "construction specifications" as
applied to a golf ball means all of the constructions specifications
involving the construction of a ball other than materials or processes
used to impart enhanced micro surface roughness to a ball. Balls with the
same construction specifications will have the same core size and
materials, same intermediate layer(s) size(s) and material(s), same cover
size and material, same dimple patterns (positions and sizes), etc. Balls
having the same construction specifications can be substantially
identical or differ only in having materials and/or being subject to
processes used to impart enhanced micro surface roughness to a ball. For
example, a first and second ball can have the same construction
specifications even though the first ball has no surface roughening
particles in its coating and the second ball includes surface roughening
particles in its coating. Similarly, for example, a first and second ball
can have the same construction specifications even though the first ball
has a first amount of surface roughening particles in its coating which
results in a first degree of micro surface roughness for the first ball
and the second ball has a second amount of surface roughening particles
in its coating which results in a second degree of micro surface
roughness for the second ball. For example, in the above examples, the
micro surface roughness of the second ball can be larger than the micro
surface roughness of the first ball and vice versa.

[0061] The term "smooth ball" as used herein means a ball that does not
have surface roughening particles in sufficient amount to impart
increased micro surface roughness to the exterior surface of the ball
and/or was not subject to processes to impart increased micro surface
roughness to the exterior surface of a ball.

[0062] Some aspects of this invention relate to golf balls having a top
coat or other coating over the cover layer, wherein this coating
comprises a resin having particles contained therein or applied thereon.
The particles provide a golf ball having a somewhat roughened surface
(e.g., micro-roughened), as will be described in more detail below.

[0063] If the resin contains the particles, after the resin is applied to
the golf ball body to form the coating, at least some of the particles
may protrude beyond an average thickness of the resin. In some instances,
the average size of the particles may be greater than the average
thickness of the resin. As shown in FIG. 3, generally the particles 22
protrude from the surface such that a thin portion of the resin 20 still
covers the particles. The surface of the ball will therefore be roughened
somewhat, as shown in FIG. 3. The coating 20 thickness and surface
roughness shown in FIG. 3 is exaggerated to help better illustrate
features of this aspect of the invention.

[0064] If the resin itself does not contain the particles necessary to
provide the roughened surface when it is applied to the golf ball cover
18, after the resin is applied, and prior to drying, particles may be
applied to the wet resin. The particles may adhere to and/or become at
least partially embedded into the resin, but still extend from the
surface of the resin to provide a somewhat roughened surface. As shown in
FIG. 4, in this example structure and method, particles 22 are applied to
the surface of resin 20. Again, the sizes shown in FIG. 4 are exaggerated
to help better illustrate features of this aspect of the invention.

[0065] If desired, the features of FIGS. 3 and 4 may be combined into a
single ball construction. More specifically, if desired, after the
coating process of FIG. 3, additional particles may be adhered to the
coating 20 in a process like that shown and described above in
conjunction with FIG. 4. The additional step of post coating particle
adherence (e.g., like that of FIG. 4) may be selectively applied to
certain areas of the ball (e.g., areas where lower than desired roughness
is observed) or may be applied to specific predetermined areas of the
ball (e.g., at the poles, at the seam, at areas covered or "shadowed" by
a holding device during an initial coating process, etc.). Additionally
or alternatively, if desired, as noted above, roughening particles 22 may
be included in the cover layer 16, in at least some examples of this
invention. In such arrangements and methods, the coating 20 should not be
applied so thick as to completely smooth out the areas between particles
22 in the cover 16 (i.e., so that sufficient micro surface roughness
continues to exist in the final product).

[0066] The particles 22 allow for fine tuning of and/or improvement to the
aerodynamic performance of golf balls in flight, e.g., to enable longer
flights of the golf ball, alter lift, etc. The particles cause the finish
of the coating to be rougher and on a micro-scale act as small dimples,
which is believed to increase the turbulence in the air flow around the
ball and shift flow separation to the back of the golf ball, thereby
reducing pressure drag. Also, if desired, the durability of the golf ball
may be improved both in cut resistance and abrasion resistance, e.g.,
depending on the properties of and/or materials used in the coating 20.

[0067] Given the general description of various example aspects of the
invention provided above, more detailed descriptions of various specific
examples of golf ball structures according to the invention are provided
below.

[0068] The following discussion and accompanying figures describe various
example golf balls in accordance with aspects of the present invention.
When the same reference number appears in more than one drawing, that
reference number is used consistently in this specification and the
drawings to refer to the same or similar parts throughout.

[0069] As described above, FIG. 3 and FIG. 4 illustrate aspects of the
invention related to golf balls having a top coat or other coating
comprising resin and particles contained within the resin or applied
and/or embedded thereon, respectively.

[0070] The particles may be of any shape and may be regular, irregular,
uniform, non-uniform, or mixtures thereof. The particles may be any
polygon or other geometric shape, including regular shapes, such as
spheres or cubes. The spheres may have a round cross-section or may be
flattened to provide an elongated or oval cross-section. The cubes may be
of square or rectangular cross-section. Irregular shapes may be defined
by an irregular surface, an irregular perimeter, protrusions, or
extensions. The particles may be rounded, elongated, smooth, rough, or
have edges. Combinations of different shapes of particles may be used.
Crystalline or regular particles, such as tetrapods, may also be used.

[0072] The particles may be selected to provide a desired level of micro
surface roughness to the golf ball to achieve the desired aerodynamic
qualities of the golf ball, as well as to optionally improve abrasion
resistance. The particles may be of any suitable hardness and durability.
Softer particles tend to affect spin, for example.

[0073] The average size of the particles may depend on various factors,
such as the material selected for the particles. Generally, the particle
sizes will range from 400 nm to 40 microns, and in some example
constructions, from 5 to 20 microns. In one particular example, the
particle sizes range from 8 to 12 microns. The particles may be
approximately the same size or may be different sizes, optionally within
the defined ranges. If the particles are applied to the surface of the
resin (e.g., as in FIG. 4), they would generally be smaller than if they
were contained within the coating (e.g., as in FIG. 3).

[0074] Any suitable resin may be used including thermoplastics,
thermoplastic elastomers such as polyurethanes, polyesters, acrylics, low
acid thermoplastic ionomers, e.g., containing up to about 15% acid, and
UV curable systems. Specific examples include AKZO NOBEL 7000A103. Paints
and topcoats of the types conventionally known and used in golf ball
production (e.g., as coating layer 20) may be used as the base resin to
contain roughening particles without departing from this invention.

[0075] Additional additives optionally may be incorporated into the resin,
such as flow additives, mar/slip additives, adhesion promoters,
thickeners, gloss reducers, flexibilizers, cross-linking additives,
isocyanates or other agents for toughening or creating scratch
resistance, optical brighteners, anti-yellowing agents, UV absorbers, and
the like. The amount of such additives usually ranges from 0 to about 5
wt %, often from 0 to about 1.5 wt %.

[0076] The viscosity of the resin prior to application to the golf ball
body may be about generally 16 to 24 seconds as measured by #2 Zahn cup.
Generally the resin is thin enough to easily spray the coating onto the
golf ball body, but thick enough to prevent the resin from substantially
running after application to the golf ball body.

[0077] The thickness of the applied resin (after drying) typically ranges
from of about 8 to about 50 μm, and in some examples, from about 10 to
about 15 μm. When the particles are contained within the resin, the
thickness of the resin may be less than the particle size in order to
allow at least some of the particles to protrude from the resin.

[0078] The coating contains a plurality of particles, generally, 0.1 to 30
wt % particles based on total coating weight, and in some examples, from
3 to 10 wt %.

[0079] The coating may be clear or opaque and may be white or have a tint
or hue or other coloring pigment. The particles may be of any color.
Generally application of the coating and particles to the outside of the
golf ball, if present in a sufficient amount, will give the ball somewhat
of a dull or matte finish, as compared to the brighter or shinier finish
of many conventional golf balls. The particles tend to diffuse some of
the light in a clear coat, for example.

[0080] According to one aspect of the present invention, a coating is
formed by applying and drying a resin on the surface of the golf ball
body. The method of applying the resin is not limited. For example, a
two-component curing type resin such as a polyurethane may be applied by
an electrostatic coating method, or by a spray method using a spray gun,
for example, after mixing an aqueous polyol liquid with a polyisocyanate.
In the case of applying the coating with the spray gun, the aqueous
polyol liquid and the polyisocyanate may be mixed bit by bit, or the
aqueous polyol liquid and the polyisocyanate are fed with the respective
pumps and continuously mixed in a constant ratio through the static mixer
located in the stream line just before the spray gun. Alternatively, the
aqueous polyol liquid and the polyisocyanate can be air-sprayed
respectively with the spray gun having the device for controlling the
mixing ratio thereof. Subsequently, the two-component curing type
urethane resin on the surface of the golf ball body is dried.

[0081] In one aspect, the coating comprises resin (with any additives) and
particles mixed therein. The coating is applied to the golf ball body
such as described above. Prior to application to the golf ball body, the
particles may be added to the resin as a separate ingredient, or may be
pre-mixed with one of the components in a two-component coating
composition.

[0082] In another aspect, a resin layer (with any additives) is applied to
the golf ball body such as described above. Prior to drying, particles
are applied to the top of the wet resin layer using a media blaster, sand
blaster, powder coating device, or other suitable device. The particles
may adhere to the surface and/or be embedded into the surface of the
resin layer.

[0083] In another aspect, a very thin resin layer may be applied on top of
the particles to hold the particles in place. Generally this resin layer
is composed of the same resin layer initially applied, but may have a
thinner viscosity. This additional thin layer of resin may be provided,
if necessary or desired, to fine tune or somewhat reduce the exterior
surface roughness of the ball.

[0088] In the Wet Sand Abrasion test, balls were tumbled in wet sand for 8
hrs. The balls were compared visually. Lower scores indicated less damage
to the ball. The balls were graded from 1 to 5 with 1 being the best and
5 being the worst. Attention is drawn to FIG. 5, which shows that
Inventive Sample #2 had a lower (better) wet sand abrasion score as
compared to that of the Comparative Sample.

[0089] In the Wedge Abrasion test, balls were hit with a standard 56 deg.
wedge and the degree of scuffing was visually analyzed. Lower scores
again indicated less damage to the ball. The balls were graded from 1 to
5 with 1 being the best and 5 being the worst. Attention is drawn to FIG.
6, which shows that Inventive Sample #1 had a lower (better) wedge
abrasion score as compared to that of the Comparative Sample.

[0090] The spin graphs (FIGS. 7-9) show the inventive coating can increase
spin somewhat off of irons and wedges without increasing driver spin.
This is advantageous for more distance and control off the driver (lower
spin) and more control around the green (higher spin).

Aerodynamic Data

[0091] Golf balls in accordance with examples of this invention were
subjected to various aerodynamic tests as described in more detail below.

[0092] In the following evaluation, the "surface roughness" (also called
"Ra" in this specification) of various balls was evaluated. Surface
roughness may be thought of as the arithmetic average of deviation from
an ideal surface, and it may be calculated according to the following
formula:

R a = 1 / n i = 1 n y i ##EQU00001##

where y represents the height of the surface's deviation from an "ideal
surface" at a specific location and "n" represents the number of height
deviation measurements made on the surface. The ideal surface may be
defined as the location of the perfectly smooth surface without roughness
or height deviations, e.g., the average surface location over the area
measured. In at least some instances, the ideal surface may be defined by
a "best fit" curve derived from a three-dimensional surface scan of the
ball's surface (described in more detail below) and/or derived at least
in part from CAD data representing the surface of the mold cavity from
which the ball cover is formed (optionally taking into account the
additional thickness provided by any post-mold coating(s)).

[0093] Height deviation measurements may be made in any desired number
and/or at any desired spacing around a ball without departing from this
invention. FIG. 10A provides an example of the manner in which height
deviation and surface roughness may be measured. In this example, while
an ideal, smooth surface is illustrated (which may be flat or curved,
e.g., corresponding to the curvature of a "perfect" ball or a "perfect"
dimple, shown as a broken line in FIG. 10A), the actual surface (the
solid line) is shown to have peaks and valleys. Measurements of the
actual surface location with respect to the ideal surface location are
made at constant spaced distances across the desired surface area (e.g.,
the entire surface of the ball, at selected locations around the ball
surface, within or around one or more dimples, on one or more land areas,
etc.), and that measured distance corresponds to the height in the "y"
direction that the actual surface deviates from the ideal surface at that
specific location. Then, the sum of the absolute values for these height
deviations at all measured actual surfaces is divided by the total number
of measurements taken to thereby provide an average roughness value for
the ball ("Ra"), e.g., as indicated from the formula above.

[0094] Appropriate measurements of the change in the surface height (e.g.,
height deviations) may be made using three-dimension scanning systems as
are known and commercially available (e.g., a system including a Hirox
OL-35011 lens, a Hirox KH-1300 microscope (available from Hirox-USA,
Inc., River Edge, N.J.), a COMS Remote Controller CP-3R, Hirox KH-1300
Microscope Controller, COMS Position Controller CP-310, and a COMS
CD-3R_MMMB Amplifier). Such systems are capable of making
three-dimensional models of an object being scanned.

[0095] As a more specific example, a three-dimension scanning system, like
that described above, may be programmed to take about 4900 "pictures"
around the area of a single dimple. More specifically, for a single
dimple, 70 sub-pictures may be made (e.g., with a tiling factor (picture
overlap) of 25%) over the surface area of the dimple (a 7×10 matrix
of pictures) and its immediately surrounding area, and each sub-picture
includes 70 pictures in the vertical direction (to locate the surface in
the depth direction). These pictures (and subpictures) allow for
computerized reconstruction of a representation of the actual dimple
surface.

[0096] Another term used in this specification is called "micro surface
roughness." "Micro surface roughness" is simply the Ra value described
above, but only counting deviations from the ideal surface of 0.25 mm or
smaller (although other cutoff values may be used without departing from
this invention). This parameter may be referred to herein as Rax,
wherein "x" represents the desired upper limit of deviation considered to
constitute "micro" surface roughness. Thus, deviations from the ideal
surface location of 0.25 mm or less may be referred to herein as
Ra0.25, deviations from the ideal surface of a height of 0.3 mm or
less may be referred to herein as Ra0.3, etc. The sum of all surface
roughness (e.g., with no upper limit or cut off height, with a cut off
height of 80 mm, etc.) also is referred to in this specification as
"macro surface roughness." Thus, "micro surface roughness" may be thought
of as the portion of overall or macro surface roughness contributed by
height deviations of 0.25 mm or less (or other desired upper limit, as
noted above).

[0097] Any desired manner of measuring surface roughness and/or deviation
of an actual surface from an "ideal surface" may be used without
departing from this invention to determine both "macro surface roughness"
and "micro surface roughness," although the three-dimensional scanning
system described above was used in the tests described below.

[0098] In these experiments, a golf ball model having a smooth exterior
coating was used as the control ball. This ball model had a three piece
construction with a thermoplastic polyurethane cover. For the inventive
balls, the same ball construction, dimple pattern, and materials were
used, except silica particles were incorporated into the polyurethane
clear coat applied to the balls such that the balls had a rough, matte
appearance (the control balls have this same type of coating without the
additional silica particles added thereto).

[0099]FIG. 10B provides an illustration that helps to explain certain
dimple properties as those terms are used in this specification. FIG. 10B
illustrates a partial cross-sectional view of a portion of a golf ball
cover layer 16 with a dimple 18 formed in it prior to coating (the other
layers of the ball and the coating are omitted to improve clarity). The
partial cross-sectional view of FIG. 10B is taken at a center of dimple
18 that has a round outer perimeter surface edge shape (when looking
directly down at the dimple 18 on the ball's surface). As shown in FIG.
10B, the majority of this example dimple 18 has a circular arc
cross-sectional shape. Thus, the dimple 18 is said to have a "dimple
radius," wherein the center C of this dimple radius is located outside of
the ball 10.

[0100] Dimples 18 in accordance with at least some examples of this
invention may have a sharp or abrupt corner at the junction of the
surface 16a of the cover layer 16 and the interior surface 18a of the
dimple 18. Often, however, as shown in FIG. 10B, the dimple edge will be
more rounded, e.g., having an edge radius Re. While any desired edge
radius may be provided in dimple constructions in accordance with
examples of this invention, in some more specific examples, the edge
radius Re will be in the range of 0.1 to 5 mm, and in some examples,
within the range of 0.25 to 3 mm or even within the range of 0.25 to 1.5
mm. Such dimples 18 may still be considered to have a spherical sector
shape and a circular arc cross sectional shape even when the extreme
edges of the dimple 18 have a different shape (such as a rounded corner
or edge) to facilitate transition between the interior dimple surface 18a
and the outermost cover layer surface 16a.

[0101] In dimples 18 of the type illustrated in FIG. 10B, the dimple has
no clear cut beginning or edge. Thus, as used in this specification, the
edge (or perimeter) of the dimple 18 may be determined by locating the
points E at which tangents at the exact opposite sides of the dimple 18
are parallel (to thereby provide the single dot-dash line shown in FIG.
10B labeled "Flat Cap"). These tangent points can be located, in effect,
by laying a "flat cap" down over the dimple and finding the location on
the ball surface on which this cap rests (e.g., using CAD representations
of dimples). These tangent points E define the dimple 18 edge E, and for
dimples having a round perimeter edge, the distance between the opposite
tangent points E is defined as the dimple's "diameter" as that term is
used in this specification. For dimples having other perimeter shapes
(such as polygons, ellipses, ovals, etc.), a similar dimple dimensional
size may be defined, such as length, width, major axis, minor axis, major
radius, minor radius, chord length, diagonal length, etc.

[0102] The dimple's "depth," as used in this specification, means the
dimension of the dimple from its deepest point to the tangent "flat cap"
line, as shown in FIG. 10B. For spherical sector dimples having a
circular arc cross sectional shape, this dimple "depth" will be measured
at the geometric center of the dimple 18, from the flat cap line to the
dimple interior surface 18a at the dimple 18's center.

[0103] The control golf balls (including their "smooth" polyurethane clear
coat) were used in these tests and similar balls, but with the rough
exterior clear coat (including silica roughening particles) were used
(Inventive Balls #2 described above). Two of the control balls weighed
45.3559 g and 45.3883 g, respectively, and two of the balls treated in
accordance with this invention weighed 45.7568 g and 45.7448 g,
respectively. A Mettler Toledo scale was used for the weight
measurements. While the roughened balls were on average 0.379 grams
heavier than the smooth balls (0.8% heavier), this difference is believed
to have a negligible effect on the comparative trajectories of these two
types of balls (as estimated by the estimation model provided by
Bissonnette, et al., in U.S. Pat. No. 6,729,976, which patent is entirely
incorporated herein by reference).

[0104] Any desired amount of the surface area of the ball may be measured
to determine the surface roughness (both micro and macro) for the ball.
Preferably, measurements will be made over sufficient areas dispersed
around the ball to provide an adequate sampling so that the determined
roughness values can be statistically attributed to the entire ball. For
these experiments, multiple dimples of each dimple type on the ball were
measured (including the dimple itself and a portion of its surrounding
area), and each of the measured dimples was measured two or three times.
The average of the surface roughness measurements for the multiple
measurements of each dimple was used as the result for that dimple. This
procedure resulted in the measurement of 36 total dimples (each measured
2 or 3 times, as noted above), and the measured locations were dispersed
around the golf ball surface.

[0105] In some example surface roughness measuring tests for this
invention, the roughness of at least 7.5% of the ball's overall surface
area will be measured, optionally in at least 36 discrete areas dispersed
around the ball surface, and this measured surface roughness will be
considered the surface roughness of the entire ball. For some measurement
techniques, the discrete areas will be centered on or fully contain a
dimple, and measurements will be made on at least six different dimples
of each size (provided that the ball has at least six dimples of each
size, and if not, all dimples of that size will be measured). The dimples
measured should be dispersed around the ball (e.g., dimples on opposite
sides or hemispheres of the ball) so as to provide a good overall
estimate of the surface roughness. Dimples are considered to be of the
"same size" if the dimples are intended to have the same size and shape
after they are molded (e.g., the same perimeter shape, profile shape,
depth, height, diameter, diameter to depth ratio, etc.) and before
coating takes place. Dimples will be considered to be of the "same size"
if the CAD or other "blueprint" data for making the mold cavity for
forming the dimples indicates that the dimples are intended to have the
same size and shape.

[0106] The macro and micro surface roughnesses of the control balls and
the inventive balls were measured using scanning equipment as described
above, and the measurement results for one dimple size are shown in FIGS.
11A and 11B. As shown in FIG. 11A, the macro surface roughness Ra is
substantially the same for both balls (each having an Ra80mm of
about 46 to 47 μm). This stands to reason because the ball's dimples
constitute the main contributor to macro surface roughness as the ball's
overall surface roughness is dominated by the presence of the dimples
(i.e., the overall surface roughness contribution due to the
microparticles is small as compared to the overall surface roughness
contribution due to the much larger dimples). Notably, however, as shown
in FIG. 11B, the dimples on the two ball types have significantly
different micro surface roughnesses (Ra0.25mm, in this example). The
noted dimples of the smooth, control balls had a micro surface roughness
of about 0.6 μm, while the corresponding dimples of the balls
including the silica particles to roughen their surface have a micro
surface roughness of about 1.9 μm.

[0107] Additionally, the macro and micro surface roughnesses of another
dimple type of the control balls and the inventive balls were measured,
and the measurement results are shown in FIGS. 11C and 11D. As shown in
FIG. 11c, the macro surface roughness Ra is substantially the same for
both balls (each having an Ra80mm of about 45 to 46 μm). Notably,
however, as shown in FIG. 11D, these dimples on the two ball types have
significantly different micro surface roughnesses (Ra0.25mm, in this
example). The noted dimples of the smooth, control balls had a micro
surface roughness of about 1.0 μm, while the corresponding dimples of
the balls including the silica particles to roughen their surface have a
micro surface roughness of about 1.96 μm.

[0108] The following Table provides the average micro and macro surface
roughnesses as measured for the various dimple types on the control
"smooth coated" ball and on the inventive "rough coated" ball:

[0109] Thus, the roughened ball had more than 1.75 times the micro surface
roughness (Ra0.25mm) as compared to the same ball construction
without a roughened final coating (e.g., without silica particles
provided in and/or adhered to the polyurethane clear coat), while the
macro surface roughness remained relatively constant. For some of the
measured dimples, the roughened ball had more than 2 times and even more
than 3 times the micro surface roughness as compared to its smooth
counterpart. As noted above, as used herein, balls will be considered to
have the "same ball construction" if they are made to the same
construction specifications with the exception of the roughening material
incorporated into the structure (e.g., same core size and materials, same
intermediate layer(s) size(s) and material(s), same cover size and
material, same dimple patterns (positions and sizes), etc.).

[0110] At least some advantageous aspects of this invention (as will be
described in more detail below) may be realized for roughened balls that
have at least 1.75 times the micro surface roughness (Ra0.25mm) as
the same ball construction without a roughened final coating, and in some
examples, in balls having at least 2 times the micro surface roughness
(Ra0.25mm) or even at least 2.5 or 3 times the surface roughness
(Ra0.25mm). Micro surface roughness may be measured in any desired
manner, provided it is measured consistently on the two ball surface's
being compared and is capable of measuring height deviations less than or
equal to the desired micro surface roughness limit. Also, the
three-dimensional scanning process described above may be used for
measuring dimple micro and macro surface roughnesses.

[0111] The dimple scanning process described above found that, for dimples
of the same type (e.g., comparing the measured E dimples noted above),
the roughened (inventive) ball had slightly deeper dimples (on average)
as compared to the smooth (control) ball (e.g., about 158 μm v. 150
μm, respectively, for Dimple Type E and about 152 μm v. 146 μm,
respectively, for Dimple Type F). Typically, for dimples of a common
diameter (with other factors being equal), shallower dimples (and an
increased dimple diameter to depth ratio) will lead to higher
trajectories. See, T. Sajima, et al., "The Aerodynamic Influence of
Dimple Design on Flying Golf Ball" in Springer (ed.) Engineering of Sport
6, pp. 143-148, which article is entirely incorporated herein by
reference. From this "conventional wisdom," due to its somewhat deeper
dimples, if any ball trajectory change is noted, one would expect the
roughened (inventive) ball to have a lower trajectory as compared to its
smooth (shallower dimpled) counterpart control ball. As shown in the ITR
data described below, however, the roughened ball in accordance with this
invention in fact had a higher trajectory than is smooth counterpart.

[0112] The aerodynamic performances of the golf balls were tested using an
Indoor Test Range ("ITR") corresponding to that used by the United States
Golf Association ("USGA") for testing golf balls for conformance with
USGA rules. This equipment and the USGA testing procedures are commonly
known and used in the golf ball art, so further detailed description will
be omitted. This system is capable of measuring and/or determining the
non-dimensional parameters of Reynolds number ("Re") and Spin Ratio
(S.R.) at which each ball is launched, as well as the coefficient of lift
("CL") and the coefficient of drag ("CD") experienced by the
ball during its flight. For ITR measurements in this experiment, in
accordance with typical practice, six balls of every ball type (i.e., the
smooth, control golf ball and the modified rough coated version of this
same ball) were shot through the ITR system, and each ball was shot in a
"seam orientation" (i.e., seam aligned with a vertical plane and oriented
in the direction of launch) and a "pole orientation" (i.e., seam aligned
with a horizontal plane). Moreover, the balls were launched through the
ITR system at 15 different Reynolds number and spin ratio combinations
(for a total of 180 ITR shots and measurements per ball type), ranging
from Reynolds number of about 72,000 to Reynolds number of about 220,000.
The fifteen Reynolds number and spin ratio settings corresponded to those
used in conventional USGA testing.

[0113] The launch conditions, initial velocity, starting angle, and spin
for driver shot simulation during some ITR testing were set to about 266
km/h (242 ft/sec), 11.3°, and 44.7 revolutions/sec (2682 RPM),
respectively, to mimic launch conditions of a typical professional golfer
(these are average driver launch conditions measured in 2009 on the PGA
Tour). Various other launch conditions also were tested, e.g., at various
different Reynolds number and spin ratio conditions, as noted above.

[0114]FIG. 12 is a graph showing the measured coefficient of lift to
coefficient of drag ratio (CL/CD) over the tested range of
Reynolds numbers using ITR testing for the smooth coated (control) balls
and the rough coated (inventive) balls with the balls launched in the
pole position. Notably, the roughened (inventive) balls displayed a
higher CL/CD ratio over all or substantially all of the
Reynolds number range tested. The difference in CL/CD ratio is
most prominent at the extreme ends of the test ranges. For example, as
shown in FIG. 12, at a Reynolds number of about 72,000, the smooth
control ball had a CL/CD ratio of about 0.84, while the
roughened (inventive) ball had a CL/CD ratio of about 0.91
(more than an 8% higher CL/CD ratio). Also, at a Reynolds
number of about 205,000, the smooth control ball had a CL/CD
ratio of about 0.70, while the roughened (inventive) ball had a
CL/CD ratio of about 0.73 (more than a 4% higher
CL/CD ratio).

[0115] The difference in trajectories (vertical) between these two ball
types (with the balls launched in the pole orientation) is illustrated in
the graph of FIG. 13, which shows a plot of ball height against ball
flight carry yardage. Notably, the apex of the roughened (inventive) ball
is about 1.4 yds (1.28 m) higher than that of the smooth (control) ball.
The overall difference in carry length is 1.46 yds (1.33 m), with the
roughened (inventive) ball having the longer carry. The following Table
provides some additional data obtained during ITR testing of these two
types of balls.

Notably, the ball in accordance with the example of this invention has a
longer carry, a longer flight time, and a higher apex.

[0116]FIG. 14 shows a plot of the coefficient of lift (CL) for the
two ball types tested under the above noted driver launch conditions for
FIG. 13 throughout the flight (in the pole orientation), and FIG. 15
shows both the trajectory curves (from FIG. 13) and the coefficient of
lift data (from FIG. 14) in a single graph plotted against the carry
distance. Notably, these figures show an increase in the coefficient of
lift throughout almost the entire ball flight trajectory. More
specifically, as shown in these figures, early in the flight (e.g., at
launch and inside 80 yards of carry), the roughened (inventive ball) has
a higher coefficient of lift than the control ball. As a golf ball is
launched with backspin, the lift force helps get the ball into the air
and fly farther because the lift force counteracts against gravitation
forces pulling the ball back down to the ground (and thus, depending on
spin conditions, a higher coefficient of lift at launch can be
beneficial, at least for some players). From about 100 yards to 165 yards
of carry, the coefficients of lift for the two ball types are
substantially the same. As the balls reach their apexes (e.g., from about
170 yds of carry and beyond), however, dramatic differences in the
coefficient of lift are shown. More specifically, as shown in FIGS. 14
and 15, the roughened (inventive) ball maintains a relatively high
coefficient of lift beyond the flight apex (e.g., greater than or about
0.26) as compared to the coefficient of lift for the control ball (which
dipped to about 0.22). Moreover, the roughened (inventive) ball's
coefficient of lift remains higher than that of the control ball
throughout the balls' descents. This is shown in FIG. 15 by the vertical
separation of the CL curves beyond the upper peaks in the trajectory
curves (i.e., to the right of line P located at the area of the
trajectory peaks of the two balls). Maintaining as high a coefficient of
lift as possible at the end of the ball flight (i.e., after the ball's
apex) is desirable for at least some players because this tends to keep
the ball up in the air a little longer during descent, thereby providing
longer carry distances (e.g., balls having low coefficients of lift after
the apex tend to have a flight that appears more like "dropping out of
the sky").

[0117] Notably, FIGS. 14 and 15 also show that the coefficient of lift for
the roughened (inventive) ball reaches its peak or maximum (CL Max)
at a greater carry distance (about 200 yds) than the location of the
coefficient of lift peak or maximum (CL Max) for the control ball
(at about 173 yds). Thus, in this example, the roughened ball experienced
an increased coefficient of lift and an increasing coefficient of lift
through a longer portion of the ball's flight (as compared to the control
ball).

[0118] The following Table provides some additional ITR test results and
data (measured as described above) for both the pole and seam
orientations for golf balls in accordance with examples of this invention
and their smooth coated counterparts.

[0119] According to one embodiment, micro surface roughness can be
imparted on a golf ball by roughening the exterior surface of the ball
through abrasion to include deviations in the exterior surface of the
ball in a sufficient amount such that the micro surface roughness of the
ball is increased. The method of abrading the ball is not limited and
includes various methods of subjecting the ball to abrasion by contact
with abrasive material. Example methods of abrading include rubbing the
ball against an abrasive material, rolling or tumbling the ball against
an abrasive material, and/or blasting the ball with abrasive material.
Abrasive material can include, for example, a loose aggregate of abrasive
particulate (e.g. sand, crushed minerals, etc.), a bonded abrasive, a
coated abrasive (e.g. sand paper), a pumice, a sharp surface, wire or
other stiff bristles or brushes, and/or a scored surface.

[0120] Roughening of a golf ball through abrasion to impart increased
micro surface roughness on the ball can be performed using a golf ball
roughener having an abrasive material. Referring to FIGS. 16A and 16B, in
one embodiment, the golf ball roughener is a rotable tumbler 30. The
rotable tumbler 30 can include a drum 32 having an inside surface 34 and
an outside surface 36. The inside surface 34 can define an inside volume
35 within which, for example, at least one golf ball 10 can be contained.
The drum 32 can be rotated about a center axis 38. The drum 32 can be
rotated manually by, for example, turning a handle 31 connected to the
center axis 38 or spinning the drum 32. The drum 32 can also be rotated
automatically by, for example, use of a rotary motor. The inside surface
34 and/or inside volume 35 of the drum 32 can include an abrasive
material 39 for subjecting a golf ball 10 to abrasion. The inside surface
34 can include an abrasive material by, for example, having the abrasive
material, such as sand paper 39, coated on the inside surface 34. The
inside volume can include an abrasive material by, for example,
containing an amount of loose aggregate of abrasive particulate, such as
an amount of sand or an amount of sand and water, within the inside
volume. The ball 10 can be subjected to abrasion by, for example, placing
a ball 10 inside the drum 32 and turning the drum 32 to cause the ball 10
to contact the abrasive material 39. Turning the drum 32 at greater
speeds can cause the ball 10 to tumble against the abrasive material with
greater force by bouncing and rolling against the abrasive material and
can thereby incur increased number and depth of deviations in the
exterior surface in less time. The interactions with the abrasive
material 39 also may be increased by providing vanes or other structures
on the inside surface 34. The terms "rolling or rolled," "tumbling or
tumbled," and "bouncing or bounced" as used herein in the context of a
golf ball contacting an abrasive material are used synonymously.

[0121] The number and depth of deviations introduced to the exterior
surface of the golf ball by using a rotable tumbler 30 can depend on, for
example and among other variables, rotations per minute of the drum, the
amount of time the ball is tumbled within the drum, the physical
properties of the abrasive material, the construction specifications of
the golf ball, and the construction specifications of the drum 32. In one
embodiment, the rotable tumbler is provided with a plurality of
correlations between at least one performance parameter and micro surface
roughness for at least one type of golf ball. The at least one
performance parameter can include, for example, aerodynamic properties of
golf balls disclosed herein, such as spin, height, carry, coefficient of
lift, coefficient of drag, and ratio of coefficient of lift to
coefficient of drag. The correlations can further include correlations
between rotations per minute of the tumbler, tumbling time, and resulting
micro surface roughness for the at least one type of golf ball. The
correlations can include other variables, such as those described
throughout this disclosure. The correlations can allow the user to
identify, for example, a desired performance parameter, such as increased
carry, the amount of micro surface roughness needed for the ball to
exhibit such parameter, and determine what rate of rotation and tumbling
time for the rotable tumbler 30 will impart such amount of micro surface
roughness to the ball 10. Such correlations for a specific tumbler and
ball construction can be determined, for example, empirically.

[0122] Referring to FIG. 16c, in an embodiment, the golf ball roughener is
a container 40 with a lid 41. The container 40 can have a body 42
defining an inside volume 43. Securement of the lid 41 on the body 42 can
seal contents within the container 40. An abrasive material such as an
amount of loose aggregate of abrasive particulate 44, including sand or a
mixture of sand and water, can be contained within the container 40.
Additionally or alternatively, if desired, one or more walls of the
container 40 and/or the interior of the cover 41 may be made roughened
and/or include exposed abrasive material. The container 40 can be rotated
or shaken to abrade the ball 10 with the abrasive particulate 44. The
container 40 can be rotated in multiple ways, such as around a center
axis, a horizontal axis, or both. As with the rotable tumbler described
above, the amount of deviations introduced to the exterior surface of the
golf ball 10 by using the container 40 to increase the micro surface
roughness of the ball 10 can depend on, for example and among other
variables, rotations per minute, the amount time the ball is subject to
abrasion within the container, the physical properties of the abrasive
material, and the construction specifications of the golf ball. In one
embodiment, the container 40 is provided with a plurality of correlations
between these variables and other variables, such as those described
throughout this disclosure and, for example, the example variables
identified above for the rotary tumbler.

[0123] Referring to FIG. 16D, in an embodiment, the golf ball roughener
utilizes a plunger 50 for rubbing a golf ball 10 against abrasive
material. The plunger 50 can include a first end 52 and a distal end 54
opposite the first end. The plunger 50 can include a handle 51 proximate
the first end 52 and a golf ball holder 53 in between the first end 52
and the distal end 54. The holder 53 can be a hole defined in the
plunger. The holder 53 can be dimensioned to accommodate and hold a golf
ball 10 such that the ball can rotate within the holder 53. The plunger
50 can further include a housing 55 containing abrasive material 56. The
abrasive material of this example structure can be abrasive bristles 56.
The abrasive bristles can be positioned in the housing 55 such that a
golf ball 10 positioned in the holder 53 contacts the abrasive bristles
56 when the distal end 54 of the plunger is inserted into the housing 50.
Inserting the plunger into and drawing the plunger out of the housing can
subject the ball 10 to abrasion by the abrasive bristles 56 and thereby
impart deviations into the exterior surface of the golf ball 10.

[0124] As with the example golf ball rougheners described above, the
amount of deviations introduced to the exterior surface of the golf ball
10 by using the plunger and abrasive bristles can depend on, for example
and among other variables, the number of times the ball is rubbed against
the bristles, the physical properties of the abrasive material, and the
construction specifications of the golf ball. In one embodiment, the
plunger is provided with a plurality of correlations between these
variables and other variables, such as those described throughout this
disclosure and, for example, the example variables identified above for
the rotary tumbler and the container. In addition to structure in which
the ball 10 is contacted by bristles arranged in a substantially linear
orientation (and the ball is moved in a substantially linear manner) as
shown in FIG. 16D, the bristles may be arranged in a circular path and
the ball may be moved around this circular path by a rotary motion, akin
to the structure and arrangement of certain types of golf ball washer
structures.

[0125] In an embodiment, heat can be applied to the golf ball during
roughening to increase the susceptibility of the exterior surface to
incurring deviations by abrasion. In an embodiment, a heat source can be
included with a golf ball roughener. The correlations mentioned above
also may include information regarding heating of the ball and/or the
abrading chamber in which the ball is placed.

[0126] In an embodiment, a home appliance dryer can be used as a golf ball
roughener. For example, the inside surface of the drum of the dryer can
be lined with an abrasive material. Such an abrasive material can be, for
example, an abrasive sheet having a first side including the abrasive
material and a second side including an adhesive material. The abrasive
sheet can be dimensioned to cover at least a portion of the vanes of the
drum or at least a portion of the surface between the vanes of the drum.
The amount of deviations introduced to the exterior surface of the golf
ball by using a home appliance dryer can depend on, for example and among
other variables, rotations per minute of the drum, the amount of time the
ball is tumbled within the drum, the physical properties of the abrasive
material, the construction specifications of the golf ball, and selected
temperature of the drying cycle. In an embodiment, a plurality of
correlations between these variables and other variable, such as those
described throughout this disclosure and, for example, the example
variables identified above for the rotary tumbler, can be provided. In
one embodiment, a set of correlations can be provided between at least
one performance parameter, micro surface roughness for at least one type
of golf ball, and settings for the home appliance dryer with the abrasive
material installed therein. In an embodiment, the correlations described
above can be provided on a website on the Internet.

[0127] In an embodiment an instruction device includes one or more of the
correlations mentioned above. The instruction device in various
embodiments is an instruction sheet, a computer device (portable or
stationary) including a memory storing the correlations, a website or a
portion of a rotable tumbler that instructs a user to access a website.

Selective Micro Surface Roughening

[0128] In an embodiment, and as described above, increased micro surface
roughness can be selectively applied to specific predetermined areas of
the ball. The predetermined area can be less than a surface area of the
entire exterior surface area of the ball. Surface area not included in
the predetermined area can be referred to as the "remaining area," so
that the "predetermined area" and the "remaining area" comprise the
entire exterior surface area of the ball. Example predetermined areas can
include an area covering at least one of two opposite poles of the golf
ball, an area covering at least a portion of a seam of the golf ball, an
area covering at least a portion of the lands between dimples of the golf
ball, and an area covering at least a portion of one or more of the
dimples. In an embodiment, the area covering at least a portion of one or
more of the dimples can include the edges of one or more dimples. The
micro surface roughness of the predetermined area can be selectively
increased such that the micro surface roughness of the predetermined area
is larger than the micro surface roughness of the remaining area. For
example the predetermined area can have a micro surface roughness at
least 1.20 times larger than the micro surface roughness of the remaining
area. In one embodiment, the predetermined area covers 7.5% to 50% of the
exterior surface area of the golf ball. In one embodiment, the
predetermined area covers 50% to 75% of the exterior surface area of the
golf ball.

[0129] Referring to FIGS. 17A-17H, examples of predetermined areas of golf
balls having micro surface roughness larger than that of the remaining
areas are depicted. The opposing poles are identified with the letter
"P," the seam line is identified with "SL," and the predetermined areas
are identified with stipple shading. FIGS. 17A and 17B depict an example
of a golf ball having a predetermined area covering two opposite poles of
the golf ball, wherein the predetermined area covering each pole is in
the pattern of a dome. FIG. 17c depicts an example of a golf ball having
a predetermined area covering at least a portion of the seam line of the
golf ball, wherein the predetermined area is in the pattern of a
continuous band encircling the ball at the seam line (although the band
could be discontinuous or include gaps within it, if desired). FIG. 17D
depicts an example of a golf ball having a predetermined area covering a
portion of the seam of the golf ball, wherein the predetermined area is
in the form of a band encircling the ball in a position transverse to the
seam line and around the poles of the ball. FIG. 17E depicts an example
of a golf ball having a predetermined area covering two opposite poles
and covering the seam of the golf ball, wherein the predetermined area is
in the pattern of a first band encircling the ball at the seam line and a
second band encircling the ball in a position transverse to the seam line
and covering the poles. FIG. 17F depicts an example of golf ball having a
predetermined area covering at least a portion of the seam of the golf
ball, wherein the predetermined area is in the pattern of a dome covering
a portion of the seam line (e.g., a dome centered on the seam line). FIG.
17G depicts an example of a golf ball having a predetermined area
covering at least a portion of the interior surface one or more dimples.
FIG. 17H depicts an example of a golf ball having a predetermined area
covering at least a portion of lands between dimples of the golf ball. In
one example, the land area between dimples can include the edges of the
dimples.

[0130] In an embodiment, the predetermined area can be in the form of a
symmetrical or asymmetrical pattern on the exterior surface of the golf
ball. In the context of describing patterns of micro surface roughness,
"symmetrical" as used herein means having correspondence in shape and
relative position on opposite sides of the golf ball. For example,
referring to FIGS. 17A and 17B, and where 17B depicts both the top view
and bottom view of the ball of 17A, the dome patterns covering each pole
are symmetrical in that the patterns cover an area of the same shape and
are in the same relative position on opposite sides of the golf ball. For
example, referring to FIG. 17F, where the dome pattern is included on one
side of the ball alone, the pattern is asymmetrical.

[0131] Micro surface roughness can be selectively applied to predetermined
areas of the golf ball according to several methods. In an embodiment, a
coating comprising resin (with any additives) and surface roughening
particles mixed therein can be selectively applied to the predetermined
area golf ball body, e.g., by spraying the coating material onto the golf
ball cover layer. In another embodiment, a resin layer (with any
additives) is applied to the golf ball body and, prior to drying, the
surface roughening particles can be selectively applied to the
predetermined area on the top of the wet resin layer. In another
embodiment, an ink that includes surface roughening particles mixed
therein can be selectively applied to a predetermined area of a golf
ball, such as a logo, player number, side stamp, geometric pattern or
other indicia. The ink including surface roughening particles can be
stamped on the cover of the golf ball or can be stamped over the coating
of the golf ball. In another embodiment, the predetermined area can be
roughened through mechanical abrasion, e.g., as described above in
conjunction with FIGS. 16A through 16D (which can predominantly and
selectively place the micro surface roughness in the land areas, as shown
in FIG. 17H). In an embodiment, the predetermined areas shown in stipple
shading in FIGS. 17A through 17H have micro surface roughness at least
1.2 times larger than the micro surface roughness in the remaining area
(non-stippled area). In an embodiment, the predetermined areas shown in
stipple shading in FIGS. 17A through 17H have micro surface roughness at
least 1.2 times larger than a comparable ball having the same ball
construction but without increased micro surface roughness (smooth ball).

[0132] In an embodiment, a stencil can be used to cover a portion of the
exterior surface of the golf ball during roughening. The stencil can
leave exposed the predetermined area for selective roughening and cover
the remaining area to protect the remaining area from being roughened or
being subject to further roughening. In other words, a stencil can
"shadow" or "mask" areas of the ball on which increased micro surface
roughening is not desired while allowing the exposed areas of the ball to
be roughened.

[0133] Referring to FIG. 18A to 18C, an example stencil 60 for defining a
predetermined area on the exterior surface of golf ball in a pattern of
symmetrical domes is shown. The stencil 60 can include a top portion 61
and a bottom portion 62, which when joined to contain the ball therein
completes the stencil. The stencil can also be made of a single elastic
piece that can be fitted over the ball 10. The stencil 60 covers the
exterior surface of the golf ball except for the predetermined area such
that the stencil leaves exposed the predetermined area to roughening and
protects the covered area from roughening. In the example shown in FIG.
18C, the stencil leaves exposed an area covering the two opposite poles
in the pattern of symmetrical domes.

[0134] Referring to FIGS. 18D and 18E, an example stencil 70 for defining
a predetermined area on the exterior surface of a golf ball 10 in a
pattern of a band encircling the ball is shown. The stencil 70 can have a
top portion 71 and a bottom portion 72 that when positioned on the ball
in symmetrical fashion leave exposed the pattern of a band encircling the
ball. In the example shown in FIG. 18E the stencil leaves exposed an area
covering the seam of the golf ball.

[0135] Referring to FIGS. 18F and 18G, an example stencil 80 for defining
a predetermined area on the exterior surface of a golf ball 10 in a
pattern of the dimples is shown. The stencil 80 can have a top portion 81
and a bottom portion 82 which include holes defined therein that can
correspond to the pattern of the dimples 18 on the ball 10. In the
example shown in FIG. 18G the stencil leaves exposed an area covering the
dimples 18.

[0136] In one embodiment, an example stencil can define a predetermined
area on the exterior surface of a golf ball 10 in a pattern of an area
covering at least a portion of the lands between the dimples 18. The
stencil can have a top portion and a bottom portion which include open
areas defined therein in the form of areas covering the area of the lands
between the dimples 18. The stencil can include covers for covering the
area of the dimples 18. The open areas and covers of the stencil
cooperate to leave exposed the area covering at least a portion of the
lands between the dimples and cover the remaining area during roughening.

Optimized Micro Surface Roughening

[0137] In an embodiment, aspects of micro surface roughness can be
optimized so that a ball having a specific set of specifications exhibits
a particular enhanced aerodynamic property. Also, in an embodiment,
aspects of micro surface roughness can be optimized so that a ball
exhibits a particular enhanced aerodynamic property in accordance with a
peak condition for such property as compared to comparative balls having
different aspects of micro surface roughness. The term "aerodynamic
property" and "performance parameter" can be used synonymously and
include aerodynamic properties and performance parameters discussed
above, such as spin, height, carry, coefficient of lift, coefficient of
drag, and ratio of coefficient of lift to coefficient of drag. For
example, aspects of micro surface roughness can be optimized so that a
ball exhibits the longest carry as compared to comparative balls having
the same ball construction but different aspects of micro surface
roughness. In addition, for example, aspects of micro surface roughness
can be optimized so that a ball exhibits an increased coefficient of lift
throughout its trajectory as compared to comparative balls having the
same ball construction but different aspects of micro surface roughness.
In addition, for example, aspects of micro surface roughness can be
optimized so that a ball exhibits an increased post-apex coefficient of
drag during decent (which can also be referred to as post-apex
coefficient of drag) as compared to comparative balls having the same
ball construction but different aspects of micro surface roughness.

[0139] In an embodiment, aspects of micro surface roughness exhibit
different enhanced aerodynamic properties or different degrees of
enhanced aerodynamic properties according to different golf ball
constructions specifications. For example, golf balls having the same
aspects of enhanced micro surface roughness and the same construction
specifications except for, for example, dimple pattern may exhibit
different degrees of enhanced aerodynamic properties. Accordingly, in an
embodiment, micro surface roughness can be optimized for each ball of
different construction specifications. In an embodiment, micro surface
roughness can be optimized for balls having the same construction
specifications except for dimple pattern.

[0140] In an embodiment where an increase in the value of the performance
parameter reflects an enhanced performance parameter, a golf ball having
optimized micro surface roughness exhibits a performance parameter that
is at least 95% of a peak performance parameter The peak performance
parameter can be determined from, for example, the largest increase in
the value of the performance parameter exhibited by: a first comparative
ball without enhanced micro surface roughness (smooth ball), a second
comparative ball of the same type as the smooth ball having micro surface
roughness of about 2.0 times larger than the micro surface roughness of
the smooth ball, a third comparative ball of the same type as the smooth
ball having micro surface roughness of about 3.0 times larger than the
micro surface roughness of the smooth ball, and a fourth comparative ball
of the same type as the smooth ball having micro surface roughness of
about 4.0 times larger than the micro surface roughness of the smooth
ball. In an embodiment where a decrease in the value of the performance
parameter reflects an enhanced performance parameter, the peak
performance parameter can be determined from, for example, the largest
decrease in the value of the performance parameter exhibited by the
first, second, third, and fourth comparative balls as described above.
The percentage increase or decrease in which a ball having optimized
surface roughness exhibits in comparison to a comparative ball of the
same type without enhanced micro surface roughness (smooth ball) can vary
according to a particular ball construction specifications and/or the
particular performance parameter. Similarly the percentage of the peak
performance exhibited by a ball having optimized surface roughness can
vary according to a particular ball construction specifications and/or
the particular performance parameter.

Examples for Micro Surface Roughening of NIKE® 20XI-X Golf Balls

[0141] Golf balls of the same type were prepared in accordance with
variable aspects of micro surface roughness as disclosed herein. As
discussed above, golf balls of the same type have the same ball
construction, including same dimple pattern. The aerodynamic performance
of the golf balls were tested using an indoor test range ("ITR")
corresponding to that used by the USGA for testing golf ball for
conformance with USGA rules.

[0142] The type of golf ball used was the NIKE® 20XI-X ("20XI"). The
20XI is a four piece construction ball with a resin core. The 20XI
includes a dimple pattern having 360 dimples prepared in accordance with
aspects of U.S. patent application Ser. No. 13/184,254 filed Aug. 20,
2010, which is entirely incorporated herein by reference. A regular
commercially available 20XI ball was used as the control ball and
referred to in this example as "Control."

Examples and Test Results

[0143] Five 20XI balls were prepared in accordance with aspects of
roughening the exterior surface of the ball with an abrasive material.
Balls R, S, Q, and T were placed in a jar with 22/3 cups sand and 22/3
cups water and tumbled for 1, 2, 3, and 4 hours respectively. The type of
sand used to prepare R, S, Q, and T was Fujilunduma available from Fuji
Manufacturing Company Limited, Fujioka JP. Ball U was placed in a jar
with sand and water and tumbled for 4 hours. The type of sand used to
prepare U was QUIK, All-Purpose Sand #1152, QUIKRETE, Atlanta, Ga.
Roughening performed by tumbling the balls in a mixture of sand and water
as described above was found to impart deviations predominately at the
lands and edges of the dimples without altering the interior surface of
the dimples significantly. Accordingly, values of micro surface roughness
based on measurements taken in the dimples of balls roughened by mixing
in sand and water may not reflect the extent of micro surface roughness
imparted on the edges of the dimple and lands of such golf ball.

[0144]FIG. 19 includes micro surface roughness (Ra0.25mm)
measurements for balls S, T, and U. The micro surface roughness values
for balls in FIG. 19 were derived from measurements taken in various
dimples dispersed around the surface of each ball. Accordingly, the micro
surface roughness values of balls S, T, and U shown in FIG. 19 may not
reflect the extent of micro surface roughness imparted on the dimple
edges and lands of each ball.

[0145]FIG. 20A provides ITR data showing differences in total carry and
roll in yards in comparison to the control ball for balls R, S, Q, T, and
U for three driver shot simulations with different launch conditions in
pole and seam positions. Balls R and S showed increased carry and roll
for all but one launch condition. Ball U showed increased carry and roll
for all launch conditions.

[0146]FIG. 20B is a graph showing the measured coefficient of lift to
coefficient of drag ratio (CL/CD) over the tested range of
Reynolds numbers using ITR testing for the Control ball and Ball U with
the balls launched under a driver shot trajectory simulation with launch
conditions of 258 ft/sec, 11°, and 33.3 revolutions/sec in pole
position. Notably, roughened Ball U displayed a higher CL/CD
ratio throughout the post-apex phase of the tested range and parts of the
pre-apex phase of the tested range, the apex being at about Re 85 k.

[0147]FIG. 20c is a graph showing the measured CL/CD ratio over
carry in yards for the Control ball and Ball U with the balls launched
under a driver shot trajectory simulation with launch conditions of 258
ft/sec, 11°, and 33.3 revolutions/sec in pole position. Again,
roughened Ball U displayed a higher CL/CD ratio throughout the
post-apex phase of the range and parts of the pre-apex phase of the
tested range, the apex being at about 170 yards.

Examples and Test Results

[0148] Five 20XI balls were prepared in accordance with variable aspects
of applying a coating having resin and a plurality of surface roughening
particles mixed therein to a golf ball body to produce coated golf balls.
Balls V and W were coated with a clear coat resin having amorphous silica
particles with particle size up to 5 μm. Balls X, Y, and Z were coated
with a clear coat resin having 15 percent by weight crystalline silica
particles with a particle size of up to 40 μm, 125 μm, and 160
μm, respectively. FIG. 19 includes micro surface roughness
(Ra0.25mm) measurements for balls V-Z. The micro surface roughness
values for balls in FIG. 19 were derived from measurements taken in
various dimples dispersed around the surface of each ball.

[0149]FIG. 21A is a table showing the measured pre-apex, post-apex, and
overall average CL/CD ratio for balls V, W, X, Y, and Z under
driver shot trajectory simulation with launch conditions of 258 ft/sec,
9.7°, and 46 revolutions/sec (r/s) and 242 ft/sec, 11.3°,
and 44.7 r/s in pole position. FIGS. 21B, 21C, and 21D plot in graphical
form the CL/CD ratios shown in the table of FIG. 21A according
to the corresponding micro surface roughness values of the balls. The
graph of FIG. 21B shows the overall average CL/CD ratio versus
micro surface roughness (Ra), the graph of FIG. 21c shows the pre-apex
CL/CD ratio versus Ra, and the graph of FIG. 21D shows the
post-apex CL/CD ratio versus Ra. Notably, balls V, W, and X
exhibited increases in overall average CL/CD ratios versus the
control. Ball V has micro surface roughness about 2 times larger than the
Control and balls W and X have micro surface roughness about 3 times
larger than the Control. Ball V exhibited the largest increase in overall
average CL/CD ratio at 0.7% increase over the control. Balls Y
and Z having micro surface roughness of about 4 times larger than the
control exhibited decreases in overall average CL/CD ratio
versus the Control. Accordingly, at 0.7% larger than the Control, the
overall average CL/CD ratio of 0.852 for ball V is the peak
value for the comparable balls tested.

[0150]FIG. 21E is a graph showing the measured CL/CD over the
range of Reynolds numbers from ITR testing of balls V, W, X, Y, Z, and
Control launched under a driver shot trajectory simulation with launch
conditions of 258 ft/sec, 9.7°, and 46 r/s in pole position. FIG.
21F is a graph showing the post-apex phase of balls V, W, X, and Control
of the test results shown in FIG. 21E.

[0151] The range of Reynolds number occurring during the driver shot
trajectory of an average professional player is usually between 65 and
220 k. Reynolds numbers are proportional to the travelling velocity of
the ball and therefore the highest Reynolds numbers occur right after
club-ball impact. One can divide the trajectory into a pre-apex and a
post-apex phase. While these two phases are time-wise usually
approximately of equal length, their ranges of Reynolds numbers differ
significantly.

[0152] Due to the complex nature of fluid dynamics in the boundary layer,
subtle changes of the surface properties of the golf ball may alter
aerodynamic parameters such as coefficient of drag and coefficient of
lift significantly within a certain range of Reynolds number without
having significant influence on other (higher or lower) ranges of
Reynolds numbers. These subtle changes may be realized by adapting the
surface on a micro scale (applying micro surface roughness of specific
Ra).

[0153] Since certain changes in micro surface roughness seem to alter the
aerodynamic parameters only within certain ranges of Reynolds number it
is, at least in parts, possible to optimize aerodynamic parameters within
certain sections of the trajectory without major changes in other ranges
of Reynolds number. This might affect the carry, roll, total carry
positively. Also the nature of the trajectory might be tailored to
specific needs of certain golfers such as a higher or lower apex. Another
possibility would be to alter the carry at apex. The influence of
different launch conditions needs to be considered as well and might be
another possibility to individualize trajectories for certain players.
These considerations are consequently not only applicable to driver
shots, but iron and wedge shots.

[0154] FIGS. 21G and 21H are tables showing additional ITR test results
for balls V, W, X, Y, Z and Control for driver shot trajectory simulation
with launch conditions of 242 ft/sec, 11.3°, and 44.7 r/s in pole
position (FIG. 21G) and seam position (FIG. 21H). Notably, ball V
exhibited the greatest increase over the control with 0.1% increase in
apex, 0.7% increase angle, and 0.4% increase in time when shot in the
pole position and 0.3% increase in carry and 0.5% increase in total yards
when shot in the pole position. Ball Y exhibited the greatest increase
over the control in roll with 19.9% increase in roll and 22.4% increase
in roll for the pole and seam positions, respectively. Based on the
example results for 20XI ball, in one embodiment, micro surface roughness
value of 0.8-1.8 μm is beneficial for increasing driver shot carry and
roll for the 20XI ball. In addition, a micro surface roughness value of
1.0-1.5 μm is beneficial for increasing total carry for the 20XI ball.

[0155] The golf ball body of the present invention has no limitation on
its structure and includes a one-piece golf ball, a two-piece golf ball,
a multi-piece golf ball comprising at least three layers, and a
wound-core golf ball, including balls with different constructions,
materials, and the like. Moreover, the present invention can be applied
to any type of dimple pattern, including patterns with at least some
non-round dimples (e.g., polygonal dimples, asymmetric dimples, dual
radius dimples, etc.). The present invention can be applied for all types
of the golf ball.

CONCLUSION

[0156] The present invention is described above and in the accompanying
drawings with reference to a variety of example structures, features,
elements, and combinations of structures, features, and elements. The
purpose served by the disclosure, however, is to provide examples of the
various features and concepts related to the invention, not to limit the
scope of the invention. One skilled in the relevant art will recognize
that numerous variations and modifications may be made to the embodiments
described above without departing from the scope of the present
invention, as defined by the appended claims. For example, the various
features and concepts described above in conjunction with the figures may
be used individually and/or in any combination or subcombination without
departing from this invention.